Means and method for controlling motive forces



1943- R. A. PRESTON 2,325,707

MEANS AND METHODS FOR CONTROLLING MOTIVE FORCES I Filed March 4, 1940 L2 W 46 32 4 4 44, 22 o 0 34 Q L W W 7114 IN'VENTOR Tro EY.

Patented Aug. 3, 1943 MEANS AND METHOD FOR CONTROLLING MOTIVE muonsRobert A Preston, Pasadena, Calif. Application Ma ih' 4 1940;SC1'PAINO;

6 Claims.

An object of the invention is' to provide ower means automaticallybrought into being to control movement of a power shaft in rotary orlineal movement whereby a distributor such as a valve or a timing devicemay be moved to and from an assumed standard or starting point.

Another object of the invention is to'provide means to control a drivenactuator recurrently through cycles of operation wherein each cycle ofoperationis divisible into segments hayin" either equal or unequalmagnitude depending" or upon service requirements.

Another object of he invention is to provide means tocontrol a drivenactuator recurrently through cycles of operation wherein each cycle oioperation is divisible into segments having unequal magnitude, that is,where a first segment of an operating cycle is of minimum value, where ac trically opposite segment of operation is maximum value, where anintermediate segment of operation is of less than maximum value, andwhere a second intermediate segment of operation is of more value thansaid minimum value, although of less value than said other interme-("slate segrl ent of operation.

Another object of the invention to to provide means to control a drivenactuator recurrently' through cycles of operation wherein each cycle ofone on isdivisible into segments thereof having unequal values, andwhich actuator when moved clock-wise will have a first operable positionof min um value, a diametrically opposite or third operable position ofmaximum value, asecond segmental position or a position interme- .ionsin moving clock-wise which is of less than maximum value, and a fourthsegmental position of operation or a position following the third priorto the first mentioned position which great r value than'said firstmentioned egmenal position or minimum value position,

of less value than said second menmental position.

A further object of the invention is to'provide electrical circuitswhich may be energized upon lusion or attainment of a maximum and/or ll"mum and/or intermediate condition of temperature, pressure, humidity,luminosity. etc., to ope ate an impulse unit whereby the their uumand/or minimum and/or in-' tion will be reversed and/or advanced from1.- through the ten existing partial cycle of prevailing condition.

Other objects, features, and advantages of the and invention may appearfrom the-accompanying drawing and specification which" are onlyillu's'f' trative of the instant form thereof, and the appended claims.I I In the drawing, of Whi h there is one sh eeti Figure l is aschematic View showing essen'- tial construction to effect control ofadrivenshait within the purview of this invention;

"Figure 2 'is a detail taken substantially on line 2' 2, in- Figure 1,showing the magnet in con junction" with one of the camsadapted toeffect circuit interruption as contemplated to partially control'tliedriven'el'ement lshaftL Figures 3; 4; 5; ah'd 6 show in schematic a1"-rangement the impulse unit driven element (shaft) in each of foursuccessive positions and the positions assumed by the cams thefeomeachofthe'positions-belng or epresenting a different point to effect controlof the circuit shown in Figure" 1. Q N f Theu'se towhichth'eapparatus-of thls'inven tion is put, it is believed, he stated as beingmatter of choice" and depends" upon the task hand, however, ss matterpfback-grdtmd and to give substantiationof usefulness, one ap--'p'lieat'ion may-besta'ted to bea'me'ans to'remotel f control-3fregulator or valvein' a steam-heating system for an auditorium where theprimary heat" admitting valveis' actuatedby a power impulse base'd uponelectricalenergy. In regarem the above reference to a control valve, itmay be mentioned,- that withinthe spiflt' o'f-this specific referencemay be mentioned dampers and other types of"regulators ,and that suchregulator regardless of asnamreanemmi tionm'ay be formed to entirelycut-Orr passage therethrough when moved to any extreme open or'f closedposition, and likewise; as probably would be thecase' in a: majority ofinstallations,- it may be rormedto provide for variable degrees 03'passage 0" bleeding therethrough' when in QI Yclosedor intermediateposition. This theory ofope rat ion heing- \vithin the scope of the artcovering valves and regulatorsin general will be fully appreciated by;those conversant therewith.

The present illustration oi this invention, as in many other types ofcontrol is shown as utilizinga thermostat which is set for an-acceptedstandardicondition oftemperatu-re, and such standard regardless of itsdegree is reflected-in the position in which-ltheidrlven cam shaftof theimpulse unit- (motor) is" placed, veachibelng complementary tothe-other; even'thougha-lag-may occur in the onewhile-followingtheother; and in this respect it is to be riotedthatpressure gages hy'grostats;

etc.,'may beused with equal facilitydepending only upon the servicerequirements.

The apparatus as here set forth includes an 7 impulse unit 20 providedwith a'directly actuated shaft 22, although a clutch could be interposedbetween the shaft and the impulse unit. Cams or interrupters 2 3, 26,28, 39, 32, and 34 are positioned upon, although electrically insulatedfromthe shaft 22 and are pre-formed with such conventional shape as toprovlde'for lift in time and interval in raising and permittinggravita-' V 'tional lowering of the several fingers 3t, 38, 48, ,7

:32, 44, and fitas may of necessity be required.

the metallic base 58 is joined to the terminal I20 of magnet 14 by leadI22, while a lead I24 joins the terminal post I26 of base 56 and theterminal post I28 of the impulse unit 20.

Assuming that the shaft 22 of the impulse unit 20 is operativelyconnected with a four-way valve or other analogous control device in aheat 2 ing system and that the thermostat 62 is suitably located, in anauditorium, to which the above mentioned valve directs steam or otherheating medium, dependent only upon open, or partially open, or closedposition thereof, and that the thermostat is electrically connected withthe im- A breaker point 48 is carried on each of the fingersaforementioned and they in turn are operatively mounted'upon a block ofinsulating material till. Points 52 are complementary-to each of thepoints lB'and as shown in Figure 1, are grouped in separate electricalzones. The contact points 52 of fingers 36, 38, and 40 are secured in asingle metallic base 56, while the points 52 of fingers t2 and M aresecured upon asecond separate metallic base 58, while the:

point 52 of fingers '45 is secured upon a third metallic base 63. Allvof these bases being mounted uponan insulating'block 54.

"A thermostat or other automatically operated device 62 remotelysituated from the aforementioned apparatus is so formed and adapted toclose and open certain electricalcircuits to energize. and dc-energizecertain of the above mentioned fingers, aswill be subsequently set forth1 in detail, suffice to here state that the contacts as and 66 securedin supports 68 are adapted to alternately and/or as may be required. bychanging conditions, complete an electrical circuit when the movableelement or bar Id of the automatically operated device 62 is moved toclose either of the contacts E i and 66, or is moved'to an intermediatepoint without contacting either one'of the contacts.

i I A magnet Ti t-is adapted to periodically hold thefinger-3fiain"elevated position when energized for the purposeof'breaking aparallel circuit to; th impulse unit when thecontacts 65and 65:

arenot closed, as and for the subsequently set forth purpose.

The foregoing structurewhile simple in nature,.

comprises the physical structured the appara tus ofthis invention whentaken together with the essential inter-connected circuit wiring,.adescription of which will now follow, reference being had to thedrawing.

pulse unit operated assembly previously outlined, and that the valve(not shown) is set to continu admission of heat when the thermostat isinitially in the position indicated by the reference contemporary withthe hot side of the thermostat and the circuit energized by the closureof the r contact 66 has already resulted in movement of the impulsevunit. so as to at least partially close thevalve against further fullheat rate admission.' Also, fingers 3E, 33, and 5E3 are parallelfeedersfio c-nergize theimpulse-unit 2@, while fingers and c l a-reparallel feeders. to energize the magnet I i which co-acts with cam 24to periodically lift finger 36 to interrupt a fiow of 7 power. throughthe finger to the impulse unit,

' kill the entire electrical system followingthe opening of switch 95. v

@Thefinger as will be' shown, acts in-the nature of anautomaticallyoperated switch to The cain position shown in Figure 3 are ar rived atesthe result of the bar it moving, bc-

cause of temperature drop, to the full line or intermediate positionshown in Figure l. and the accompanying opening of contact for uponopening of contact 5 2, the circuit through finger As shown in Figure l,a lea c1 39 connected with r a source of power (not shown) is directlyconnectedwith the impulse unit 29 at terminal post 82 while a lead 84joined to lead 88 at point '86 is connected to one of the terminal posts38 of the magnet 74. Lead 911 which is complementary to lead Bill, isjoined to the terminal 92 upon the metallic base 66, while lead il lhavin a switch 96 is joined to lead 96 at point 98, and is'connectedwith the thermostat 52 by an intermediate lead me, and with the finger46 at point H12v by means of a second intermediate lead IllI. A

- gear speed reducer 2% is adapted to obtain a reduction in rotation ofshaft 22 as compared withthe motor 20,- I a .-The lead 96 is also tappedat point. I04 and this connection or lead: IE6 is directly connected tofinger 36 at. point Ii!3. -The. contact point r 64 is connectedwith'fingers ii] and 42 at-point IIll by lead II2, while contact pointBGis cont nected with fingersg38 and A l at point; I'IA by means of thelead IIB. Terminal post IIS; upon 52 is'dead, hence the magnet isde-energized and the finger 3t falls to closeits contact point 52, thus.closing the circuit through lead 5% and energizing the impulse unit,whereby it is rotated from the position shown in Figure 6 to that shownin Fi re 3, whichlatter figure forms the beginning of his. descriptionof operation.

Reference to Figurefi will show that the static position ofthe cam shaft22 andthe impulse unit 22, is the result of lobe 2 30. having raised thefinger and thus breaking the circuit to the impulse unit.

As the temperature of the room or auditorium 1 rises, the bar ii -oi thethermostat moves from intermediate position to the contact 6%, therebyenergizing lead'IiS and fingers 3B and 1 both of which ,are'in' closedposition because of the non-functional position of cams 2 2 and 32 (seeFigure 6);, hence magnet circuit A comprising lead lie, finger. andleadsl22 and 86, is energized and holdsjthe fingert i invopen circuitposition. Simultaneously. through finger 38 the impulse unit isenergized through circuit B com- 1 prising lead I I6, finger- 33, andleadiZfl, thereby 5, and 6 are each representative For as previouslystated, this position is rotating or actuating the same, and during thisrotation cam 26 has moved from a non-functional position to a positionto lift finger38 (see Figure 3) which action breaks circuit B .to theimpulse unit and the system comes to rest, having carried its entrainedvalve to closed or partially closed position depending only upon theconstruction of the valve and its passages. It is to be noted thatduring this cam movement that cam 32 is still in non-functionalposition, that is, it does not lift the finger 44, hence the magnet "i4-is still energized through circuit 'A and remains energized as long asthe contact 86 remains closed, however, upon a sensible increase intemperature the'thennostat actuated contact 85 will automatically openand break circuit A to the magnet. The finger. 35 will then drop andclose its contacts 48 -52 and since the lead W is always energized, theimpulse unit through circuit C comprising lead lflfipfinger 24 and leadI24 will be again motivated and caused to move through another segmentof its cycle of operation, which results insofar as the cams areconcerned, in the movement of cam 35 from lifting to non-liftingposition (see-Figure 4) thus preparing for closure of circuit Dcomprising lead H2, finger 42, leads 22 and 84, of the magnet 14 uponthe next subsequent closure of contact 64.

lllike'vvise'catzn 28, see Figure 4, is also in nonlifting position,hence the finger 49 is circuit closing position pr paratory to the nltisubsequent energization resulting from closure of contact 64. Also,the past movement of the cam shaft has carried cam lobe 24b tofunctional position in that it now supports the finger 35, therebydeenergizing the impulse unit through the parallel circuit C. I

From the foregoing it will appear that the impulse unit is not onlyat'rest, but that it has now carried its entrained cam 28 to suchposition as to enable energization of circuit l=,;comprising lead H2,finger 4B and lead 124] to the impulse unit upon further drop oftemperaturein .the place being heated or serviced by the system.

Closure of contact 64 will energize the fingers 4D and 42 with theresult that the magnet "E4 is again energized through circuit D to holdfinger 35 in open circuit (circuit C) position, thereby preventingmovement of the impulseunit through this circuit which is parallel tocircuits E and B,

also, it results in energizing the impulse unit through finger 40(circuit F), which aside from againactuating the associated valveor-other mechanism also, moves the cams preparatory to the nextsubsequentenergization of parallel power circuit C.

Accordingly'cam 28 moves finger ac to break the power circuit E to theimpulse unit, and cam 30 is further moved through the non-functioningposition of its travel which still leaves the finger 42 in circuit(circuit D) closing position and hence holds the finger in open circuit(circuit C) position as long as the magnet isenergized,

however, cam lobe 24b has moved to a positionwhere it-no longer supportsthe finger 35 so upon de-energiza tion of the magnet the finger 36 willagain .(all and close the parallel power circuit C through lead 185 toenergize the impulse unit 20.

The just described condition will prevail during the period that thecontact 64 is closed, for such closure insures continued energization ofmagnet 74 and non-energization of the impulse unit 20 through theparallel circuit C; however, upon a sensibledrop of temperature the bar"10 0fv the thermostat will move to an intermediate position therebyopening contact 64 which deeenergizes the magnet circuit A through leadH8 which permits finger 35 to drop and close circuit C, and actuatingthe impulse unit through another segment of its cycle. This movementresults in the cam release of fingers 44 and 38 preparatory to the nextclosure of contact 66. It also results in rotation of the cam 24 to apoint where cam lobe 2411 supports the finger 36 in elevated positionthereby breaking the power source to the impulse unit so that it is nowbrough to rest al.- though the fingers 44 and 38 are in position (seeFigurefi) to carry an energizing current to the impulse unit upon thenext closure of contact 66.

Upon conclusion of any period of operation, if 0 should be desired todiscontinue operation of he control system, as during the night, it isonly necessary to open the switch .95, thereby killing the circuits H2and H-3 through 9.4, however, lead is directly connected to post- 92,plate 69, points 48-52 on finger 46, the finger 46, post I32, and leadill! to the previously mene tioned lead N38 to the thermostat 2 from.which point the system is fed as previously described, thus forming afeed back, and permitting and effecting energization thereof until suchtime as the cam 35 is rotated by the shaft 22 to lift the finger 49 andbreak the circuit through the ts- 4S- -52 thereon, thus killing theentie system until such time subsequently thereto as the switch 55 may beagain closed. Thus it will appear that this element ofthBxQCIllblilEltlGIl is merely an automatically operated switch whichwould kill the circuit once in ea h cycle of operation if it were notfor the po itive connection afforded by the switch .96.

In rsum, it may be stated that the system of this invention essentiallycompris of power driven cams which are a in such sequence as to open andclose cert paral, lel circuits as to enable an electrical energy impulseunit to intermittently function to manipulate a control valve tomaintain a relatively constant condition.

In the present embodiment of the invention, a thermostat is shown as ameans to periodically close and open circuits for the above outlinedpurpose, cbviouslyother instruments may be used with equal. facility,depending only upon the service to he maintained, for instance,hygrometers, hydroroeters, gages, and 'barorneters, etc., may be usedwith equal facility to open and close prime sources of power forutilization in the system.

It is also to be noted that the thermostat 32 in the embodiment of theinvention shown, ,comprises or forms a three-way switch, 101 the points54a and 5511 each form a pole or terminal of the directional circuitswitch symbolized by the bar lithe third leg of the referred tothree-way switch resides in the negative fact that upon arrival of thebar I0 in a neutral position, the mast.- net 14 is deeenergized in allcases so that the finger 35 closes its contacts 48.52 thus closing theimpulse circuit through lead I05. which action carries the systemthrough another segment of its repetitious cycle. Thus, by reason of theabsence of a condition, i. e., circuit closure at 64 or 66, anadditional and parallel'circuit is closed which in its sequence is asvital of the circuits completed through contacts 64 and B6.

In conclusion it may be stated :7; obvious that various .changes andmodifications may be made in practicing the invention in departune fromthe showing of the drawing and description as given, without however,departingfrom the true spirit of theinvention as defined by the scope ofthe appended claims.

It is to be understood that the interrupters or cams maybe so shaped asto cause one or more of the fingers to make or break their contactsooner or later or remain open or closed for a longer or shorter time,as long as their relation to one another is not disturbed, and thislatitude of operation is to be considered as not departing from thespirit of this invention.

I claim:

1. In a system of control adapted to regulate periodic electric poweractuation of a shaft for functional use, said system having anelectrical impulse unit and an automatic switch with contact pointsindividually closable as one power source whereby movementiof saidimpulse unit may be had, and another circuit to effect movement of saidimpulse unit, said last mentioned circuit being operative upon openingof either of said contacts whereby a finger is gravitationally movableto close a parallelcircuit to said'impulse unit, and a cam to open saidlast mentioned circuit upon subsequent actuation of said impulse unit. r

2. In an electric control system adapted to regulate a power impulsewith respect to a given standard of departure, a motor having a shaftprovided with cams, circuit closing fingers actuated by said cams,amagnet functionally co-oparabl with one of said cams to move anassociated finger from closed circuit position, and a remotelypositioned switch closable upon attainment of a given standard, saidswitch upon closure of one of its contact points being so conmentionedcircuit energization being efiected by opening of the closedswitch polewhereby said magnet is de-energized and said single finger ismagnetically released to complete its circuit to said impulse unittoactuate thesame and said shaft through a segment of a cycle ofoperation, and means repetitious of said first mentioned switchcontactclosure to effect further energization of said impulse unit and shaftrotation througha further segment of a cycle of operaiton.

4. In an electrical controlsystem to regulate theuseful position of amotor driven mechanism, in combination, a motor having a shaft providedwith cams, motor circuit fingers actuated by said cams, a magnetfunctionally co-operable withone of said fingers, and a'remotelypositioned plural circuit switch in circuit with said fingers andclosable upon attainment of a predetermined standard condition andadapted to be opened upon attainment of a predetermined Variant of saidstandard condition, said system being electrically connected whereby themotor is actuated upon closure of one of the circuits of said switchwhereby said mechanism is moved through a par-' tial cycle of operation,and means to further rotate said motor through-a parallel circuitfollowing opening of said switch through its closed circuit whereby saidmechanism is further actunected to certain of said fingers as toenergize I a circuit to said impulse unit and said magnetwhen certain-ofsaid cams are in finger releasing position whereby said impulse unit isactuated throughone of its circuits, and a. parallel circuit thereto isd e-energized whereby said impulse unit is actuated and certain of saidcams are moved to lift the then energized fingers and break said impulseunit and magnet circuits, and another circuit closable upon magneticrelease of the finger actuated by the magnet whereby said parallelcircuit to said impuls unit is again energized. V

3. In a control system adapted to regulate movement of a driven shafthaving cams thereon, electric circuit closing fingers adapted to bemoved to open circuit position by said cams, an

7 impulse unit to actuate said shaft and cams, a

magnet, a switch having circuit closing contact pointsand being actuatedto, closed and open po sition by'a sensible change of temperature, afirst group of said fingers being in circuit with said impulse unit,said magnet and one of said switch poles, a second group of said fingersbeing in circuit with the other of said switch poles, said impulse unitand said magnet, a single finger in series with said impulse unit and apower source, said cams being positioned upon said shaft in suchsequence of function with respect to each other that upon closure of acircuit through one or said contacts said magnet will be energized tolift said single finger to open circuit position and will energize theother. finger of the group to actuate said impulse unit and shaftpending development of cam rotation to break the circuit ated in asegmental portion of a cycle of operation, said last mentioned meanscomprising a circuit parallel to said last mentioned circuit and beingoperable upon de-energization of said magnet followingopening of saidremotely positioned switch. a

5. In an electrical system including a motor, in combination, means toprovide intermittent electrical impulses whereby said motor may beactuated in a constant direction, said means comprising a motor, a shaftextending from said motor, cams on said shaft, and electrical contactmaking fingers, said fingers being actuatabl in one direction by saidcams whereby electrical circuits to said motor may be closed, a solenoidto hold said fingers in open circuit position in timed sequence withrespect to actuation by said cams, and a thermostat, said thermostatbeing provided with a plural number of electrical contacts in serieswithcertain of said motor circuit closing fingers, and another circuit, saidlast mentioned circuit being parallel to said first mentioned circuitsand being independent of the contacts on said thermostat, certain ofsaid circuits being separately energized'in timed sequence to said motorupon closure of certain of said motor actuated fingersand upon closureof an associated thermostat contact, the other of said circuits to themotor being energized upon closure of a certain one of said motoractuated fingers independently of the contacts on said thermostat.

6. In an electrical system including a motor in combination, meansto'direct intermittent electrical impulses whereby said motor may beactuated in a constant direction, said means including a conditionresponsive switch connected with a power source and having two parallelcircuits extending therefrom, a cam shaft, said cam shaft beingactuated' by said motor, a pair of contact fingers connected with eachof said parallel cir-- cuits, said fingers being moved to open circuitposition by certain of the cams on said cam shaft in response to motoroperation, one of the fingers of each of said pair of fingers being incircult, with said motor, a solenoid, said solenoid being in circuitwith one finger of each of said pairs of fingers, a single finger, saidsingle finger being connected with a power source and in parallel withsaid switch to form a third parallel circuit to said motor, all of saidfingers being intermittently actuated in sequence by said cams, saidsolenoid being functionally coopera'ole with one of said ca-ms to movesaid single finger out of circuit to said motor, said system beingenergized upon closure of said condition responsive switch wherebyenergy flows through one of said parallel circuits to said motor and tosaid solenoid to lift said single finger and de-energize said thirdparallel circuit. said cams being so positioned upon the cam shaft thattheir sequence of rotation breaks the said energized parallel circuitafter a predetermined period of motor rotation, said single fingeractuating cam being non-functional at the termination of said period ofrotation to release said single finger upon de-energization of saidsolenoid to close said third parallel circuit whereby the motor is againmoved through the remainder of it predetermined range of rotation inresponse to initial closure of said condition responsive switch.

ROBERT A. PRESTON.

